Fuel leaking into Weber. Gravity/level?

This ought to be an interesting discussion...

Seems if the float valves are working properly you wouldn't have this problem. A mechanical shut-off is a good idea. Old VWs and Porsches all had them for a reason. I often smell raw gas when I'm driving which makes me think something is not right with my float valves. I'm pretty new to this and dual webers so hopefully we will get some expert replies.

Be sure to check your oil level too. Make sure it hasn't gotten higher and that the oil doesn't smell like gas. Gas draining into the intake could find its way into the crankcase.

Is this the first time you topped off the tank?

If your jar or fuel line was below the level of fuel in the tank the fuel would siphon out of the tank causing the line to continue to drain.

If the needle and seat for the float were stuck open both venturis would most likely be wet with raw fuel.

Is the fuel dripping from the pump jet at #3 cylinder only? or #4 also?

Taking the above into consideration the problem can be narrowed down.

Not the first time I topped off, and not the first time I have seen this issue.  But it is the first time I have associated the two. I have had the carburetor rebuilt and the float replaced. It seems to be leaking at the junction between the two carbs, then dripping down the intake.

I only noticed fuel pooling in the venturi of #3.  #4 was dry, as was #1 & 2

Chances are the fuel line is still under pressure after you shut down the ignition. If you're using an electric fuel pump, install an on/off switch. Then turn off the switch a few seconds before turning off the engine, that'll relieve the pressure.

Make sure your gas tank is vented. In the summer months an unvented gas tank can stay under pressure due to the warm ambient temperatures.

90% of the time it is **** in the fuel, as in dirt,rust etc. and it is in the needele & seat letting the fuel pass right by. I run 3 filters, 1 befor the fuel pump and 1 right befor each carb, I use the cheep clear plastic ones(not the screw togeather ones), I change them each year. the other possiabilty is 1 the crabs need rebuilding(not likely )or 2 the float level is too high. but it's usualy crap in the fuel from rust or a fuel line that was replaced and not cleaned befor instalation. or from the rubber lines just coming appart, thus the need for 3 filters, to keep crap out of the fuel pump, and when the fuel pump dies the other 2 keep the crap out of the crabs. do it right do it onetime and forget about it and have fun.and dont get hurt..or cought.

 and push it out side for a day or so and pull that sparking bolt out so the fuel can dissapate,and then change your oil&filter and fix the issue, it is not just because the tank is higher than the crabs. a shut off is not the answer.but they are nice to have 1 for when the car gets stolen they only make it a mile or so &2 so when you have the fuel line disconected when putting a new engine in from the fuel in the crank case killing it, you can shut it off so it dont drip.

I clamped off the fuel line to the left carburetor and left the right carb line open to test a hypothesis.  I then wicked out all the pooled gas from the #3 venturi and cleaned the mess up. As of this morning, all venturis are dry.  Next part of the hypothesis will be to remove the clamp and see if it starts to flood again.

I ordered an inline fuel shutoff valve that is normally closed until it is powered.  I will run it off ignition hot so that when ignition is on the valve is open.  When the ignition is off the valve is closed and this should limit most of the issue.

That said, I agree there is something wrong with the float/settings.  The car runs way too rich and we are slowly working through that.  I have thought about pulling these Webers in favor of a new set of Decades.

This is a very common problem with Webers it seems. I have a dash mounted electric fuel pump cutoff switch,and installed a fuel pressure regulator. I flip the switch right when I am pulling into the driveway and let it idle for a minute or 2 and thw gas smell is gone/no drip. The FPR has a gauge and confirmed that the residual pressure combined with the carbs heat soaking/boiling up the gas,thsi is what makes it overflow the carbs. 

fix the heat issue if you have one. I would go with the empi hpmx carbs, the decades have some issues thier trying to resolve & you dont realy need to go from a carb issue to a expensive carb issue.or pull the carb& get an over haull kit($32) and some spray carb kleener and have a go at it, there realy simple carbs. as for the clamping off how did you do that??? squezing the rubber fuel line??? thats a sure way to get more crap into the carb as the rubber fractures &  go's down the line into the carb, lots of guys do this with the breaklines too and wonder why they have to replace the line that looks like new but is colapsed inside.also any fuel residue that is on the fule line walls will crumble off& go to the needel&seat of the carb. I think if you fix the issue you and your engine will be most happy, rather than masking it with a valve and it still be driping when your going down the road.

No real heat issue.  The carburetor in question has been rebuilt to include a new float valve by a reputable mechanic.  The fuel line has been completely replaced from where the fuel line exits the chassis, into the engine compartment where it passes through a good fuel filter and into a Malpassi fuel pressure regulator.  From there it tees into left and right branches which is all new.  It is very doubtful there is garbage in the fuel line.

Clamping the line?  I use a medical sponge forcep to clamp the line.  After years of clamping chest tubes, cardiac caths, and bypass lines, I am not too worried.

ok so whats the problem???if it's all been "fixed" why is it still doing it?? sorry but gravity wont do it unless your parked so the float is trying to open.

    I have seen all that done before and the new lines had crap in them or the needel&seat were not sealing due to the guy noy cleaning the old gasket off good enough.

        If it is doing it on 1 carb and not the other you have a problem with that carb. fix that carb. and after 50+ years I have seen oh somany hoses effed up by clamping them, there just rubber and tend to dryrot & crack when forced to do things they were not ment to do, or if you have ss braded teflon lines there dead fore sure now as it has a kink in the teflon and thats where they start to leek& restrict flow,I doubt you have the teflon ss breded fuel lines.

     If the new lines were not up to the new fuel blend that may also be an issue. or just a slight sliver of rubber from the cutting of the hose getting stuck in the needel, or possiably a sinking float. Did the tech weigh the float?? I have seen anybody do that in oh somany years, and I dont even know how much a webber float should weigh, I would order a new float&kit & go through that carb and check for casting flaws that my be causing the issue, there are many guys that can put a kit in any thing, but realy fixing & seeing whats going on and the reasin it is doing what it's doing....not so many any more.

       Empi had casting issues with thise first batch of idf style carbs, mostly the 40mm ones,and almost all had the rong float level, I dont know if this has ever been corected..

     Ive seen a lot of guys never check or set the float.("it was set at the factory"), not a good exsuse tor not wanting to take charge and do it.as bending little things can be stressfull, you dont want to break off a tab or snap the float in two...wtf?? if it breaks buy a good one and bill the $13 or whatever to the customer,it's all part of doing the job corectly!!!

      If you do add a stwich be sure it dosent pull to many amps off the coil. Or you could add a bypass instead of the switch so if by some chance there was too much pressure it would just releave back to the suction side thereby releaving all the presure.but I realy dont think pressure is an issue.

Its a float, not a positive stop. if the pressure in the line is higher, it will overwhelm the float.  JamesBond above seems to have the right idea - the pressure has to be bled off. Why is this one doing it when the left is not? Couldnt tell you. But this problem seems to be rampant on these sorts of carburetors as noted in the comments - but I never saw it with building high horsepower V8's using Holleys and Demon carbs.  The carb has been rebuilt and float replaced with Weber parts, so if it is still having issues it needs to be flung into the trash and replaced.

Not sure where you are buying your rubber hoses at, or what sort of clamps you are using, but I have never damaged a rubber hose by clamping it.  It that were true, fuel lines would fail with reckless abandon where they are clamped to the carburetor. We arent talking about a barn-find 65 Shelby Mustang here, we are looking at a 10 year old Speedster with a VW engine in California.  Dry rot isnt even a consideration.

Power at the coil shouldnt be an issue.  VS ran their remote oil cooler thermostat power lead off the coil and I have rewired that elsewhere.  I have also changed the coil out for a better Pertronix coil.

...might need to apply the shunt equation to troubleshoot the leak! 

I did some searching here and saw a trick about using some alcohol with food dye to see if the carb body is leaking.  I may try that as a last resort.  Obviously I cant have a carburetor leaking - aesthetics and smell aside - for safety reasons.  At some point I cut my losses and replace it.  I have changed everything else - fuel lines, filter, added a Malpassi, had the carb rebuilt.....

 I have rebuilt oh so many carbs, and seen oh somany flooding, and as of yet I have not see fuel pressure be the issue unless it had a race pump& a moron adjusting the pressure. 90% of the time it is crap in the fuel, the other 10% dead needel or sunken float.Ive seen about 10 sunken floats and those mostly rochester carbs. you must be using some spaceage fuel lines, I havent seen any go 10 years without showing sineage of cracking,spliting, shrinking, hardning etc. I use marine hose on my stuff it has the toughest uscg std's and is compatable with todays fuel. I dont think regular automotive hose has to pass anything .even the stainless braded hose has a usable life span, when it starts leeking it's dead.. so I gess your best solution is to can those carbs and get some newones to start over with, then try to figure out why 1 side has more pressure than the other side does so this dosent happen again. or just replace your fuel pump as it should not hold that much pressure, or add a good pressure regulator, then see it is not the pressure.you may infact have a cracked carb top plate, or leeking past the threads.whatever it is it IS KILLING YOUR MOTOR. if you replace the carbs Ill give you $30.00 for them just for display on my wall of old intakes& valve covers.

 I have also seen floats get stuck on the gasket ,or the drop be too much and get stuck that way too.

  and deopending on the needel some carb cleaner ace screw them up & cause them to leek, just like the strong bleach tablets to put in the toilet tank that kill the flaper valve.

   my 44'[s have floded 1 time(1 of them) when I reinstaled the top of the carb after setting float level.I just loosened the screws and taped the top around a little and that was all it took.

    is your tank vented???I cant see it not being it would run out of fuel or colaspe the tank a bit, unless it has a 1 way valve.

Well, the first and foremost issue at hand is safety.  Fuel fumes are bad news.  Spending a few hundred dollars on a new carb is cheap insurance.  Second is the enjoyability of the car.  If I am going to need to spend all my time tweaking and filtering fuel through a coffee filter, then sopping of leaks, the fun is dying away fast, and I might as well trade it in on a new Cayman. And while I agree that debris in gas isnt helpful, the petroleum industry has come light years from when these carbs were first developed and fuel has much less debris in it than it did 20 years ago.  If a gnats nut is going to hold open the float valve, we have a problem.

 well I use fuel filters to filter out the ganats nuts.1 before the fuel pump and 1 befor each carb after the fuel pump (3 total), I have no dirty fuel issues.and can see if there is water in the filters(clear plastic filter, not the screw togeather type.) easy & nothing to wory about. I have never seen anything i the two befor the carbs, but the one down at the frame horns does get a slight amount of crap that settels into the bottom(I keep them sideways, so the crap stays in the filter so you can see it, if it runs back down the line how do you know its there. fuel systems are simple but require some attn  at some time.I look at my 2 filters befor the carbs every time i look at the engine.filters are cheep repairs are not.

Lightspeed-

I'd recommend buying a set of used Dellorto DLRA 40s on the Samba. Send them to Blackline Racing (formerly ACE, Art Thraen) in Salt Lake City to be gone over by Dave. I've dorked with Webers and Kadrons-- the Dells are what you want.

Sometimes, Blackline will have a set for sale. I just bought a set of 45s from them last month. Expect to pay about $900 or more for two (not including linkage, etc.). It's a lot, but once you get past thinking of them as "used", you'll never look back.

Dellortos are all that, and a bag of chips.

What Stan said X2.  I love my Dells.  Never a hiccup and tghey run great.  I started with the HPMX faux Webers but had them changed out (ARky term) for the Dells.

Dells will probably cost  at least twice as much as the HPMX Chinese ones but well worth it.

Yep---what Stan said.  You can unload your HPMXs on ebay.

Use a mechanical shut off for now. When you feel like it, take it to a vw mechanic who still works on older vdubs to have it fixed.

If your carbs are true webers you have the best carbs that money can buy. In all the years I have worked on these carbs DCOE, IDF and IDA on VW, Porsche, Mini Cooper, Coventry Climax,Toyota, Datsun and a host of others your worst enemy is any particle that might find it"s way in to the carb circuit. Be it the main jet, idle jet or needle and seat at the float chamber. Since you have the problem at #3 cylinder ONLY it would be wise to scrutinize that portion of that carb to find your problem. Use a gas station that pumps a lot of fuel for your octane rating. Forget the band-aid fixes find the real problem. 

I did a 2017 for a guy earyler this year he sent his dells to art before art sold out, they poured fuel uppon first firing atempt.both of them. as they say **** happens.

      I have the first gen of the hpmx 44's and have no problems in 8-10 years whenever they first cam out and webbers were not avalible.they have probably close to 100000 miles on them.... or more. I my self would not pay more for dels than I can get a new set of hpmx carbs for....oh I forgot I have 2 sets of hpmx 44's, and will probably buy a set of either 48's or 51's from  the empie strikes back.

As much as I respect everybody's right to an opinion, I've got mine as well. Dellorto DRLAs are nearly perfect. The progression circuit is second to none.

Damned near like FI---and a lot less hassle.

I thought mine needed some work on the progression/transition circut & I was going to add another circut as we do on the holly 1150 cfm dominators.but befor I did any thing to them other than jetting,I fixed the flat spot curve in the 09 bosch dist. now the transition is smooth,well I think it's transisioning, I cant tell, but I doubt it would cruze at 85mph on the idle circut.and idles so smooth & clean it's probably not the main circuts.

  yes efi would be real nice to have with 52 mm throttel bodies.

     on another note cb performance just releaced thier new programable black box, so you can program your addvance curve for your engine with the dist you already have in it.it's setup for boost also.pretty neet. but over my head like most things that have electricity conected to them... ever wonder why when you turn off a flashlight at night it dosent recharge the battery??? puts out light uses battery power.....sucks in darkness should recharge the batterys..... or if your going the speed of light and turn on the flashlight will that recharge the battery?? or suck in the light till you are now going the speed of darkness?? does the expriation date on my marriage licsence mean Im now devorced?? are spelling lessons realy needed...for math? dang that was some good cheezzee.

Stan, Jack - Mahalo plenty!  I recently saw a set of used Dellortos on Craigslist here in the Bay Area for sale - cheap.  Should have bought them.

Rusty - Carb has been rebuilt by an outstanding mechanic.  http://star-tech-european.com/

Carb Wars is on!  You dudes are pushing me towards fuel injection!  LOL

Marksbug - thanks for adding some 'spice' to this thread!

Webers work just fine if you set them up right,only issues I have now is the typical clogged idle jet every now and then. I have experience with installing and tuning stand alone fuel injection systems,and they have their own issues as well,especially with the vartying temps the aircooled engines run as opposed to more rigidly thermostat controlled water cooled cars.

 If you take your time and put in some effort,the Weber carbs drive almost 95% as good as a factory modern EFI car.

 If it is running well,then you simply have to install the aforementioned cutoff switch if you have a electric pump,and run the bowls dry,you will have no more "smell". I dealt with this for over a year until I installed the Malpassi FPR and cutoff switch.I now close the garage door and get only the slightest "whiff" of any fuel fumes,which you will smell with any classic vehicle,no more "smell" than my classic BMW bikes put out after a ride..

somebody has some of the decades on the samba for 300 a set, new, they say they have 3 sets they have in use and there great. like anything new to come out these days sometimes we get to do the testing. but they do have that 10 year warranty.one of the guys st decade contacted me a few months ago about some of thier products&wanted an openion of a new product they were thinking about making, there not just copying, there trying to fill a space between what we have now and what we need, I do like the bigger fuel bowels on the carbs, thats a good addtion. if they copied the empi or even updated them some that would make for a great carb, the empis were updated over the old webers(but you cant convince a diehard webber"ex-spert"of that) I have always run twin carbd engines for well over 30 years now,mostly duell holly 4 bbls on tunnel rams or supperchargers. I was werry about webbers& that style of carbs for 3 reasons, 1 I knew nothing about them, 2 I had only worked on one 32 ford truck that had them on it, and 3 I knew nothing about them. so I got a few books on them, witch dosent realy tell you much from a real carb what does what &what does this&whats this for,&how to, molsty just reprinted stuff from days gone by, and some of that was rong. or 1 sided point of view(we all know how that is just read your thread) so after a lot of research & realy not a lot to go on I wanted a set of 44 idf's...they were now out of production... so incame the empi hpmx's I read up on them( but we all know how everything new is askuwed in the mags, and then by the diehardon ex-sperts toe other way) so I fiugured I had oh somany years building flowing modifying&racing&tuning oh so many diferent types of carbs I could change fix or modify any thing to do just what I want it to do. hear comes the good part. I ordered the hpmx 44 duel kit, the cheepest price I could find anywhere was a addvertized in hotvw's(and buggies,of corse) I think they were $469 for the compleate kit, not the delux kit but the basic, chrome air cleaner std intake kit, not the billet aircleaners&tallcb intakes, that was anouther $250. ( for a billet set of air cleaners and a set of $74. cb bigbeef intakes, not a good deal to me, so I got the intakes from cb lator when I needed a massive much better made intake for my 2332 motor) well when I called the place they tried to talk me out of them,they had somany problems with them they did not want to sell them to me, most problems were with the 40's for some reason. but he sent them to me and with zero warranty as expected. and of corse not jetted for the size carb it was, so I intaled them they ran like ****(small motor with big carbs, not jetted corectly and the flat spot in the 09 dist, made it real hell for the wife to drive)so i called empi and they sent me what ever jets I needed about 4 sets, I kinda wish I had just told them to send a compleate assortment, wtf it was free!!! but I didnt, just what I figured I needed, and then went to tuning. and got them pretty darn good for  that size carb on a small motor. then fixing the dist curve I was able to put in a lot smaller idle jets & it was so smooth now, then put them on my 2332 and rejet, then onto my 2028 and there still about one of the best sets of carbs I have ever owned, so i bought another set for my big motorgoing in the 356 ( 2387~2922cc, havent totaly decided yet) but with all my racing& carb modifying & stuff these carbs have tought me a few things that I could of done to the hollys&other carbs. other than blending the top carb plate to the main body&fitting the booster vent better to these I realy have done no mods at all, there pretty fricken good as they are. unlike the holly 4bbls where all 4 bbls flowed a lot diferent than each other and takes a good bit of work with a flow bench for equalize them I think these are pretty close. there is about 80 cfm in the holly 750 with out going to a biger butter fly, just by equlizing the flow on all 4 holes and knocking out a lot of turbulance.and that did not include inlarging the ventouri's. there is a little left in these idf style carbs, but Im not racing any more so why bother for an extra few hundrad rpm &5~10 more hp at or around 8000 rpm.

http://www.thesamba.com/vw/for...ewtopic.php?t=563525

Apparently, you aren't alone.

I read this and hope I didn't miss it, but do you KNOW the fuel pressure, like, with a gauge? Not just trusting it to be OK, actually measuring it. If mechanical pump, I've seen as high as 10 psi. Regulators can't be trusted either and must be measured. Sounds like it's above 3.5 pounds or a bad needle and seat or just dirty in my opinion.

I'm betting pressure is too high. Webers are good. Yes, Dells have a better progression circuit, but lets not throw the baby out with the bath water! I'll take the Pepsi challenge with any Dell, and we'll see whose car runs better!

DannyP,  have I measured it with a gauge?  No.  I added a Malpassi/Weber fuel regulator that it supposed to limit it to a consistent 3.5 pounds. Do I know for sure that its 3.5 lbs, no, but I have to have some faith somewhere and I have yet to see a measuing gauge that is 100% accurate.  Fuel regulator was added with an better fuel filter and al new fuel lines approximately 200 miles ago.  150 miles ago the carb in question was rebuilt, so if it is having problems already the finicky POS needs to be replaced.

I cleaned, I filtered, I tried. I still had 2 episodes of pooling on venturi #3.  Pulled the plug and it was soaked.

Thats it.  I am done with this POS Weber.

I bought a pair of Decades off eBay and will give them a try.  Got fingers crossed.

 for a tiny bit of info on regulators, we (as do most racers with an expensive motor&car) check and adjust the regulators at each event when the car is unloaded, there are many factors that can change the settings including weather&altitude. and these are $100.+regulators and the car has about 6 or more on it(4 carbs&3-4 stages of No2.) so the carbs have to be set and the No2 has to be set.I cant recall in the past 10 years the fuel perssure being spot on on any of the regulators when we check them, a few times they have been vey close.and the 16volt battery have to have a full charge befor testing to ensure the fule pump is pumping at full capisity.also the fuelcell is at very close to the same amount of fuel each time.it is all dont with the engine cold& a metered bypass line atached to each regulator to simulate wot operation.

   so to sum it up you realy need to check the pressure.dont trust any label that says what is what till you have varified it is what it is. I have no regulator on my vw stuff nor gauge,I should, but I dont,Ive never had any issue like yours,and I have no real idea how much pressure it takes to unseat the needle. for me a regulator&gauge would be to see a leen issue comming on more then a a flooding issue, as leen burns **** up and isant as easy to see smell&feal as a ritch condition is.(but I do have a o2 gauge on mine) I hope you the best with the decades,if your jetted corectly now that should also be what is needed in the decades. getter done and let us k now how it all works out.

Good luck.

I hope it works out. If it doesn't, please don't give up. Try some Dellorto 40s. Just sayin'...

Let me know what you might want for the "bad" Weber....  

What a day... good times, bad times, you know I've had my share...

Ordered new Decades, and got them Friday.  Did a side-by-side, bolt-for-bolt movement of hardware from the Webers to the Decades.  Set the Idle mixture screws at 2 turns out . Got everything replaced and back in the car and called it a night.  Got up this morning and checked, rechecked, and checked one more time the linkage and to insure everything was tight.  Turned it over and it finally fired.  It ran a bit rough so I tweaked the Idle mixture until I go the Idle right, and set the Idle screws.  Let it run a for a while to get up to temp, rechecked stuff and shut it down.  Had some lunch, did some other projects and came back to the cooled off car. Happy to notice the garage didnt smell like race pits. Pulled some plugs to check them and they had a nice color, so I decided to take it for a drive.  Nice drive through town, so I decided to get on the highway.  Just after I got on the freeway, my speedometer failed.  I should have taken this omen and gone home.

I ran up I505 about 5 miles and then decided to turn around and go back.  Everything was fine other than the speedometer, but the car was running good, the sun was out, and it was a happy day.  All the sudden all hell broke loose, and I knew all too quickly the sound of losing a rod.  The rear view blue cloud of smoke, was sort of telltale as well. Two feet in and I am looking for an exit strategy. Pull it over easily, ignition off, grab the Halon and get out.  Get back, and hope badness isnt about to happen. It doesnt.  Let it cool and open the hood.  If engines have a hell, I now know what it looks like. I lost the rod on #4and put a sunroof in the block.

Poor car is now home, in the garage.  Everyone is safe, no fire, and things can be replaced.  Need to take a break for a bit and craft a plan to replace the motor.  Look for a new post.....